How long will my boyfriend are held in jail for 5 counts of burglary 2nd, grand larceny 3rd and 2 counts of grand larceny 4th?

Burglary 2d is a B violent felony in NYS. Each count (separate residences) is punishable by determinate sentence between 5 and 25 years consecutive sentence (i.e. 5 years is the minimum. The Grand Larcenies are lesser sentences and would probably be rolled in on a settlement. If there is a trial, they may or may not be consecutive as well. I am sure by now he has secured the services of a paid attorney or appointed counsel who will look after his interest.

He probably will receive probation, however he may have to do some time in custody as a condition of probation.

You will have to ask his lawyer since there are many factors to be considered when considering a possible sentence. The real question is why are you dating a man who would commit a burglary? Has that not even occurred to you? That is a very violent and serious crime that means someone is not only a thief, but he does not respect other people or their property, do you think he will respect you? Ask your parents if they approve and see what they say, I do not know him.